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VS.B0RTON & G. H. WILLGOX.

THREAD CONTROLLING APPARATUS FOR SEWING MAGHINES." No. 255,581. Patented Mar. 28,1882.

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THREAD CONTROLLING APPARATUS FOR SEWING MACHINES. No. 255,581. Patented Ma;1*.28.1882.

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UNITED STATES PATENT OFFICE.

STOCKTON BoEroN, on PHILADELPHIA, PENNSYLVANIA, AND CHARLES H. wILLooX, on NEW Y EK, N. Y., ASSIGNORS TO THE WILLOOX & GIBBS SEWING MACHINE COMPANY, on NEW YORK, N. Y. I

THREAD-CONTROLLING APPARATUS FOR SEWING-MACHINES.

SPECIFICATION formingpart of Letters Patent No.'255,581, dated March 28, 1882, Application filed January 3, 1882. (Model.)

To all whom it may concern:

Be it known that we, STOCKTON BORTON, of Philadelphia, in the county of Philadelphia and State of Pennsylvania, and CHARLES H.

.WILLCOX, of New York city, in the county and State of New York, have invented a new and useful Improvementin Tension and Thread Controlling Apparatus for Sewing-Machines, which improvement is fully set forth in the fol- 1o lowing specification.

This invention relates to a measuring tension or apparatus which will automatically measure out the thread for each stitch, so that a uniform and elastic seam may be made 1 without special care or skill on the part of the operator. Heretofore apparatus of this desc ription has been made having a pull-off combined with two constant tensions of different force, the pullotf acting upon the thread between the two tensions, the lighter tension be ing between the spool-pin and pull-off and the heavier between the latter and the take-up. I11 the said apparatus the take-up and other stitclrtorming devices have to draw the meas ured thread through the heavier tension aforesaid, which is liable sometimes so to hold back the thread as to prevent the stitching mechanism from taking the full amount measured, and thus to render the work irregular. The 0 liability to irregular action is particularly great in sewing knit goods, for which this invention is mainly designed. In the present invention the tension between the pull-off and stitching mechanism is made automatic in its action, so

that the thread drawn by the pull-off is lei't free to be worked into the sewing, and each stitch willreceive the measured quantity. The tension between the pull-off and spool or other supply of thread is made heavy enough to pre- 4ovent, under ordinary conditions ofworking, the drawing of thread directly from the spool by the stitch-forming mechanism, and elfect the necessary tightening of the stitches. In order to insure the working of all the meas- 5 ured thread into each stitch, it is desirable to 7 leave the thread perfectly free to be taken up by the stitch t'orming mechanism; but in running from one piece of work to another the chain or series of stitches between the two pieces, being outside the fabric, do not need all the thread, and would be too loose if no restraint be placed on its delivery. Aoheckten'sion too light to interfere with the free delivery of all the measured thread so long as the fabric is sewed, but sufficient to draw up the chain properly by holding back a portion of the thread when the stitches are made outside of the fabric, is therefore arranged to act upon the thread between the pull-oft and take-up.

For convenience of reference, and to distinguish them from each other and from the checktension, the automatic or intermittent tension between the pull-off and take-up, which prevents the thread drawing back, may be called the clamping-tension, and that between the pull-off and spool, which prevents the stitch-forming mechanism from drawing thread from the spool instead of tightening the stitch in the work,the resisting-tension, The resisting-tension may be automatic or intermittent in its action; but a constantly-acting friction-tension is preferred. Any known or suitabfe device for producing a hold or tension on the tbreadsuch as weighting the spool, passing the thread through a series of eyes, and other well-known devicescan be used; but a disk-tension with disks held together by spring-pressure is preferred and is shown herein. The intermittent or automatic 8o tension can be made to release altogether the tension 011 the thread or simply relieve it in part. Whatever be the form of tension used, it is preferred to have all the tensions adjusted so that in case of an extraordinary strain upon the threadsa y in passing over a very thick scama small quantity can be drawn directly from the spool or other source of supply and breakage of the thread avoided, while with the ordinary sewing the supply of thread is ga regulated by the measuring pull-off. With some classes of work, especially in sewing stockings and other knit goods, this precaution may be unnecessary.

It may be here observed that it is common 5 to combine with an automatic or intermittent tension, as well as with other tensions, a pulloff-that is, a device auxiliary tothe takeup and other stitch-forming mechanism-which operates to draw off from the spool or its equivalent at each stitch asmall quantity of th read, so as to maintain a supply ofloose thread to be delivered to the stitch-forming mechanism; but the pull-offs heretofore usedin such combination have always been so constructed and arranged as to maintain constantly a supply of thread greater than required for the longest stitch, and have not been adapted to measure the thread for the several stitches; nor have they been arranged to operate upon the thread between an intermittent clamping-tension and aresisting-teusion, as above indicated. They have also been without adjustment, keeping supplied always the same quantity of thread to be drawn from by the stitch-forming mechanism.

As more thread is required for long than for short stitches and for thick than for thin goods, the measuring pull-offisin this invention made. adjustable, so as to be adapted to any ordinary use. It is obvious that the pull-off can be made adjustable in its action by altering the point at which it begins to pull off the thread, the movement being the same, as well as by varying the movement. The term adjustable, as here applied to the pull-oft, is to be understood broadly as referring to the adjustability of the action, and not as being limited to a pull- ,ofi' wherein the part which acts on the thread is variable, although the latter is deemed the most advantageous arrangement and is shown herein. Under this first part of the invention ameasuring or adjustable pull-off with an eye or similar device to act upon the thtead, but otherwise of any ordinary or suitable construction, can be used. The invention, however, relates also to the special construction and operation of a pull-off.

It consists, first, in'operating the pull-off from the needle-lever of the sewing-machine by means of an adjustable connection; second, in carrying the pull-oft on the needle-lever or other vibrating part of the machine and adjusting the part which acts upon the thread nearer to or farther from the fulcrum of the needle-lever, which is, of course, also the center about which the pull-off moves; third, in pivoting the pull-off to the needle-lever, so that the adjustment may be effected by turning the pull-off on its pivot; and, fourth, in looking the pulloff to prevent unauthorized alteration of its position.

The invention further has reference to the particular construction and special timing of the action of the pull-eff with reference to the stitch-forming devices, and to the special combination of the different parts of the apparatus, as hereinafter more fully set forth.

The accompanying drawings, which form a part of this specification, represent a tension and thread-controlling apparatus embodying the invention. A portion of the frame and operating parts of a Willcox & Gibbs singlethread chain stitch machine is illustrated in order to show the application; but the apparatus can be used in connection with any of the well-known machines making a chain,

Figs. 6 and 7, views in plan and vertical section, respectively, of a check-tension supported upon the base of the clamping-tension.

A is the machine-frame, and B the needlele er, operated,as usual, from the main shaft of the machine. 0 is the pull-off; D, the clamping-tension; E, the resisting-tension; F, the check-tension; Gr, a guide-bar over which the thread passes to and from the tensions and pull-off, and G a spool-pin.

The pull-off, as shown, consists of a short bar pivoted to the needle-lever B, and provided at its outer end with an eye,a,through which the thread passes. It is held in place by the large headed screw H, which passes through the needle-lever,and is tapped into theend of the pulloff. By loosening this screw the pull-off is left free to be turned on it as on a pivot, and by tightening the screw the pull-off may be held in any position to which it may be adjusted. To prevent tampering on the part of the operator or other unauthorized persons, the head of this screw is formed so that a special key is required to turn it. Thus, instead of the usual nick or groove, the screw-head is provided near its edge with two recesses, b, for receiving the prongs en the special key. Other and more elaborate means can be used, if desired, to prevent tampering, but' such as shown will ordinarily be sufficient.

In Fig. 4 a spring-washer, c, (omitted in Fig. 5,) is shown under the head of the screw H. It is of advantage, as it keeps an elastic pressure on the pull-off, even when the screw is loosened. It is also possible with it to tighten the screw sufficient to hold the pull-off in place against the action ofthe thread, while allowing it to be turned by the fingers to regulate the amount of thread which shall be pulled off from the spool at each stitch. When it is to be thus adjusted ashoulder, 0, may be formed on the screw to bear against the pull-off to prevent the screw being turned too far. the pull-off to the right (Figs. 1 and .2) the eye at is brought nearer the fulcrum ofthc needle-1ever, and consequentlyit moves through a shorter distance than before at each vibration of the needle-lever, and pulls off a less amount of thread from the spool, whereas by setting it to the left a greater length is pulled off for each stitch.

The clamping-tension D, which is intermittent in its action, may be that in common use on the Willcox &; Gibbs automatic machine;

By setting 255.581 p i a but it is preferred to have it modified, as shown in the drawings. The lower tension-disk,d,is .secured by screws to the machine-frame. The upper disk, 2, is fixed, by soldering or otherwise, to the clampstudf, and is raised at intervals against the pressure of the spring h by the eccentric-rod g acting against the clampstudf. The spring h surrounds the latter and tends to draw the tension-disks into contact. A raised seat, t, is made on the lower disk, and the thread is clamped between this seat and the under surface of the upper disk. An annular opening between the edges of the disks is thus left at all times, so that the thread can be inserted as far as the raised seat, even when the device is closed by the action of spring h. This spring bears at its upper end against the lower disk, a metal washer, k, and leather washa, forming its bearing in the hole, while it has a Ste1WHS1leI,7l/ riveted above the leather washer, which strikes flat against the cloth face of washer m.

The resisting-tension, which is constant in its action, consists of the two disksp q, the screw 0', the spring 8, andthe base-piece t. The screw 1* holds the parts together, and also attaches them, together with the spool-holder, to the machine-frame. In practice, however, the thread will commonly be delivered from above from a spool on an independent support. The thread-gnidebar Gris attached in any suitable way to the machine-frame. As shown, one end is secured on the base-piece tot the resist ing-tension.

The check-tension shown in Figs. 1 and 2 consists of two disks, to, held in place by a screw, 10, and pressed together by a spring, 00. -In1iigs.6 and 7 it consists of an annular washer, y, surrounding the head d of the clamp-stud j, which head acts as the upper disk of the clamping-tension, and two screws with springs 2, which press said washer against the disk d. Thethread is led from the spool under the guide-bar G between the disks of the resistingtension, over the guide-bar, through the eye aof thepull-offibetween the disks of the clamping and check tensions, and thence to the take up and eye of the needle. In operation, the pull-otf draws from the spool during the descent of the needle-lever the amount of thread required for each stitch, the thread being clamped by the clamping-tension, so that it is necessarily drawn from the spool through the resisting-tension. After the loop has been prevent any thread from being drawn directly from the spool. The thread is then again clamped bythe clamping-tension,and the same quantity of thread is again drawn from the thread by the pull-oft. By timing the parts so that the thread is delivered by the pull-oft gradually during the upstroke of the needle the thread is best worked into the chain-stitch, (made by the machine shown but the parts could be otherwise timed without departing from the invention.

It is obvious that portions of the invention could be used separately, and that various modifications could be made in addition to those already indicated. For example, the clampingtension could be carried by the pull-off instead of beingplacedon the machine-frame, asshown. The pull-off could be formed by an eye on the needle-lever, and a series of such eyes could be used in order that the amount measured off could be varied. In special machines which are to be used constantly on one style of work the measuring pull-ofl' need not be adjustable.

The term measuring pull-off is employed in this specification to denote apull-off,whetlier fixed or adjustable, adapted by virtue of its construction or adjustability to draw off and give up at each stitch the amount ofth read required for making a stitch, so that the pull oft measures out the thread instead of maintaining, like the pull-offsin common use, more loose thread than will be required for a stitch, and leaving it to the stitch-forming mechanism to supply itself therefrom.

In machines not usinganeedle-lever, or when, from any reason, it may not be desirable to opcrate the pull-oft therefrom, the latter may be operated from the shuttle-driving lever in machines using a shuttle, or from other moving part.

Having now fully described our said. invention, and the manner of carrying the same into eifect, what we claim is- 1. A measuring pull-0E adapted to measure at each stitch the amount of threadtherefor, in combination with an automatic or intermittent tension between said pull off and the stitching mechanism, and a tension between the spool or supply of thread and the pnll oft', substantially as described.

2. The combination, with an adj us'table pulloft, of an intermittent clamping-tension and a resisting-tension, substantially as described.

3. The combination of an automatic or intermittent tension, a constant tension, and a measuring pull-off arranged to actupon the thread between the two, substantially as described.

4. The combination, with an intermittent tension and a constant tension, of an adjustable pull-0ft arranged to act on the thread between the two, substantially as described.

5. The combination of the measuring pulloft and the intermittent clamping-tension between itself and the stitching mechanism, substantially as described.

6. The combination of an adjustable pull-ofi' and an intermittent clamping-tension between itself and the stitch-forming mechanism, substantially as described.

7. The combination of the measuring pulloff, the intermittent clamping-tension, the" check-tension, and the resisting tension, substantially as described.

8. The combination of the needle-lever, pulloit, and adjustable connection, substantially as described.

9. The combination, with a vibratory part of the sewing-machine, such as the needle-lever, of a pull-oft rigidly attached to and carried by said part, so that the eye or portion of the pull-off which acts upon the thread moves in a circular arc with the fulcrum of said vibratory part as the center, said pull-off being adjustable to bring said eye or operating portion of the pull-off nearer to or farther from thesaid fulcrum, substantially as described.

10. The combination, with a moving part of a sewing-machine, such as the needle-lever, of a pull-ofi' rigidly attached and pivoted thereto, so as to be carried thereby and adjustable on its pivot as a center, so as to alter its action upon the thread, substantially as described.

11. Theeombinatiomwith an adjustable pullstantially as described.

. 14. In an automatic or intermittent tension, the combination, with the eccentric-rod, of an independent clamp-stud and a tensiondisk fixed thereto, substantially as described.

15. In a sewing-machine forming stitches by means of a looper, a measuring pull-oft, and intermittent clamping-tension, combined with operating mechanism, and timed, as explained, so as to deliver the measured thread gradually during the ascent of the needle-bar, substantially as described.

16. The check-tension formed by an annular washer, combined with a stationary disk, supporting pins, and independent tensionsprings for holding said washer against said disk, substantially as described.

17. The combination, with an intermittent tension, of an annular spring-check tension surrounding a disk of the intermittent tension, substantially as described.

In testimony whereof we have signed this specification in the presence of two subscribing witnesses. r

STOGKTON BORTON. CHAS. H. VVILLOOX.

Witnesses:

J OHN O. PURKIS, GILMAN E. J OPP. 

